Above: Welding a steel beam at a construction site can be a tricky undertaking. Photo: Lincoln Electric, parent company of Harris Products Group.
January, 2024: Experts design safe, efficient welding gas manifold to supply multi-level facility during construction
Welding gas solutions for steel construction projects can be complicated because the equipment often is needed at multiple locations on the site, and sometimes on multiple levels of the same building.
A recent project by a global engineering and construction firm involved welding steel framing for a natural gas power generation facility. During construction of the six-story building, the construction crew wanted to maximize its efficiency by operating eight different MIG welding stations, starting on the fourth floor and moving the welders up floor by floor as the building grew taller.
The issue was how to supply the shielding gas safely and efficiently to multiple levels while keeping the gas cylinders on the ground, as there was no elevator available at this early stage of construction. Another consideration was maintaining gas pressure since the gas would need to travel as much as 75 vertical ft. to reach the top level. Worker safety was also a concern. The company consulted with its welding supply partner, Alpha Supply Inc. of Mobile, Alabama, for assistance.
PROFESSIONAL MANIFOLD
Because of these complex factors, Kelly contacted Harris Products Group for a professional manifold solution. Harris manufactures a full range of gas delivery products including flow meters, regulators, standard manifolds, valves and pigtails, as well as custom gas distribution solutions. “Joe Swenda [of Harris] intervened with his expertise and helped us with a custom manifold that we were confident would resolve the quality and safety issues,” Kelly said.
Swenda and his team developed a bespoke solution—a dual-input manifold system to supply shielding gas to eight welding stations. The manifold was housed on a lightweight, modular frame, which would make it easy to move from floor to floor. Eight flow meters were installed on the manifold to deliver the shielding gas to the welders. Flow meters were used instead of pressure regulators to ensure all welders delivered a consistent gas flow regardless of how many of the welders were using gas at any given time.
Above: A 3D CAD drawing helped the customer visualize how the custom manifold would be assembled.
Above: High-pressure regulators (Harris Model 3520-125) were installed on the outlets of the cylinder banks to regulate the gas to the proper pressure.
Because it was crucial to deliver consistent flow and pressure and avoid any deviation if all eight welders were being used at the same time, Harris designed a system that would deliver between 40 and 50 standard cubic feet per hour per welding station to satisfy the volume requirements. This system delivers more pressure and volume than needed while avoiding the possibility of a pressure decrease, which could impact weld quality in this critical structural steel application.
The team also installed check valves at the cylinder bank outlets to ensure gas purity. When the cylinder banks were swapped out, the check valves maintained pressure in the pigtails, which prevented atmospheric gases from entering the distribution system.
“Ultimately, we provided sufficient pressure and compensated for any pressure drops going up to the manifold by providing more pressure and volume than needed,” Swenda said.
ALLINONE SOLUTION
The turnkey manifold system was fabricated, assembled and tested in-house at Harris, then shipped to Alpha Supply. Once installed and made operational by Alpha, the customer successfully and safely completed the welding work.
Alpha Supply made an important choice when it decided to turn to an expert in gas manifolds, rather than relying on a fabricator to build a manifold. For the best outcomes in safety, quality and performance, it often is wiser to turn to professionals for gas manifold solutions. “Understanding the science behind gas delivery systems is critical,” Swenda said. “The use of highpressure gases brings with it inherent risks, so anyone designing a manifold should have a deep knowledge of the physics behind how gases react in different conditions as well as a working knowledge of OSHA and NFPA 51 regulations. The last thing you want on a construction site is to endanger people or property.”
Alpha Supply Inc., 888/718-4902, http://alphasupply.com/
Harris Products Group, 800/733-4043, http://harrisproductsgroup.com/
